Function initializeDirectives

packages/core/src/render3/view/directives.ts:136–246

Initializes the data structures necessary for a list of directives to be instantiated.

(
  tView: TView,
  lView: LView<unknown>,
  tNode: TElementNode | TContainerNode | TElementContainerNode,
  directives: DirectiveDef<unknown>[],
  exportsMap: {[key: string]: number} | null,
  hostDirectiveDefs: HostDirectiveDefs | null,
  hostDirectiveRanges: HostDirectiveRanges | null,
)

/** Initializes the data structures necessary for a list of directives to be instantiated. */
function initializeDirectives(
  tView: TView,
  lView: LView<unknown>,
  tNode: TElementNode | TContainerNode | TElementContainerNode,
  directives: DirectiveDef<unknown>[],
  exportsMap: {[key: string]: number} | null,
  hostDirectiveDefs: HostDirectiveDefs | null,
  hostDirectiveRanges: HostDirectiveRanges | null,
) {
  ngDevMode && assertFirstCreatePass(tView);

  const directivesLength = directives.length;
  let componentDef: ComponentDef<unknown> | null = null;

  // Publishes the directive types to DI so they can be injected. Needs to
  // happen in a separate pass before the TNode flags have been initialized.
  for (let i = 0; i < directivesLength; i++) {
    const def = directives[i];
    if (componentDef === null && isComponentDef(def)) {
      componentDef = def;
      markAsComponentHost(tView, tNode, i);
    }
    diPublicInInjector(getOrCreateNodeInjectorForNode(tNode, lView), tView, def.type);
  }

  initTNodeFlags(tNode, tView.data.length, directivesLength);

  // When the same token is provided by several directives on the same node, some rules apply in
  // the viewEngine:
  // - viewProviders have priority over providers
  // - the last directive in NgModule.declarations has priority over the previous one
  // So to match these rules, the order in which providers are added in the arrays is very
  // important.
  if (componentDef?.viewProvidersResolver) {
    // Only components can have `viewProviders`, `viewProviders` are registered first and there
    // can only be one component so we check for it specifically.
    componentDef.viewProvidersResolver(componentDef);
  }

  for (let i = 0; i < directivesLength; i++) {
    const def = directives[i];
    if (def.providersResolver) {
      def.providersResolver(def);
    }
  }
  let preOrderHooksFound = false;
  let preOrderCheckHooksFound = false;
  let directiveIdx = allocExpando(tView, lView, directivesLength, null);
  ngDevMode &&
    assertSame(
      directiveIdx,
      tNode.directiveStart,
      'TNode.directiveStart should point to just allocated space',
    );

  // If there's at least one directive, we'll have to track it so initialize the map.
  if (directivesLength > 0) {
    tNode.directiveToIndex = new Map();